Measured and predicted burial of cylinders during the Indian Rocks beach experiment

Abstract—Burial of instrumented mine-like cylinders as a result of wave-induced scour was measured during experiments con-ducted in shallow water (15-16 m) with fine-sand (133-/xm) and coarse-sand (566-/xm) sediments off Indian Rocks Beach (IRB), FL. Scour pits developed around the instrumented cylinders in the fine-sand site when significant waveheights exceeded 2 ni, causing the cylinders to pitch, then roll into the developing scour pits, often changing heading to align parallel with the wave crest. Final cylinder burial was nearly 40 cm (about 70%-80 % mine diam-eter) relative to the sediment-water interface, but only 20%-50% relative to surface area covered. The difference was caused by the lack of complete infilling of scour pits. Little development of scour pits and burial was noted on the coarse-sand site and the cylinders buried to only 20 %-40 % of the cylinder diameter below the sediment surface. Burial results, although variable, are in general agreement with the wave-induced scour model developed by Trembanis et al. (2007) for the fine sand, but not for the coarse sand where measured burial was much less than predicted. Index Terms—Cylinders, fluid flow, hydrodynamics, mine burial, scour, sediments. I